Búsqueda | SciELO

Shubnikov-de Haas oscillations are measured in a wide parabolic quantum well with 6 subbands in a tilted magnetic fi eld. We find two types of oscillations. The oscillations at low magnetic field are shifted towards higher fields with tilted angles, and can be attributed to the two-dimensional Landau state at the bottom subband. The position of the second type oscillations do not shift with tilted angles indicating a three-dimensional character of the Landau state formed by the highest subbands. The bottom level in the quantum well is not overlapped with the highest subbands due to the enhanced quantum scattering time of the lowest subbands.

We investigate the activated conductivity for Landau levels at lling factors v =1,2 in a parabolic Al xGa1-x As well down to 30 mK. We obtain a very small activation energy ~ 0.02 meV, which is almost 1-2 orders of magnitude smaller than the expected values for energy gaps in a wide quantum well. The resistivity minima vanish completely when a parallel component of magnetic field is applied. The collapse of the energy gaps in the wide parabolic well occurs due to the new electron correlated state, probably the charge density wave state predicted for a uniform wide electron slab in high magnetic field.

Cód. del Índice	Elemento
ti	título del articulo
au	autor
kw	palabras clave del artículo
subject	asunto (palabras del título, resumen y palabras clave)
ab	resumen
ta	título abreviado de la revista (ej. Cad. Saúde Pública)
journal_title	título completo de la revista (ej. Cadernos de Saúde Pública)
la	código de idioma de publicación (ej. pt - Portugués, es - Español)
type	tipo de documento
pid	identificador de la publicación
publication_year	año de publicación del artículo
sponsor	financiador
aff_country	código del país de la afiliación del autor
aff_institution	institución de filiación del autor
volume	volumen del artículo
issue	número del artículo
elocation	elocation
doi	número DOI
issn	ISSN de la revista
in	código de la colección SciELO (ej. scl - Brasil, col - Colômbia)
use_license	código de licencia de uso del artículo

No se encontraron documentos para su búsqueda